state space model has error

my A B C D matrices are:

    A =

[ 0, 0, 1.0, 0]

[ 0, 0, 0, 1.0]

[ 0, 0.15502416677813339370370805808099, -4.7863736679940324215607420213982, -0.0000033656243151182583405463328000383]

[ 0, -26.094361926054232600130044495449, -11.022752876224010373586983854075, 0.0000077508459792499219645213236865318]

B =

                                  0
                                  0
 0.88636549407296896004815441721882
 -2.0412505326340757878851343018816

C =

[ 1.0, 0, 0, 0]

[ 1.0, 0, 1.0, 0]

D =

 0
 0

when i do sys = ss(A,B,C,D)

Error using ss (line 260) The value of the "a" property must be a numeric array without any Inf's or NaN's.

Error in delete6 (line 50) sys = (ss(A,B,C,D))

this error is seen

how to solve this?

Answer 1

[Elias Hasle]

I don't know if this is relevant to your (five year old) case, but in case someone else encounters this error message: I got it after inputting data from a symbolic calculation, although the arrays did not look symbolical. Casting the arguments to double removed the error.

[Claudiu Negrau]

Thank you very much for this answer. Casting to double worked. Interesting since matlab says the data optained with the eval function is of type double, I don't know why it needed to be casted.

[Victory Friday]

Please how do you cast to double?

[Neel Dalwadi]

You can use the function double() for Matlab.

Answer 2

[Osman AKYUREK]

Hi,

I have the same error massage. I think this is because of the fact that some zeros in the matrix A. Therefore, the response of the model cannot be obtained through state-space modelling. You need to check out the matrix A. For example in my case:

if there is zero component in the matrix Mst, the same error pops up, because it is going to be infinitive value in the matrix A. I hope this helps you. Check your matrix A.

Best,

Osman

Answer 3

[Azzi Abdelmalek]

Your arrays are not correctly written

A =[ 0, 0, 1.0, 0
0, 0, 0, 1.0
0, 0.15502416677813339370370805808099, -4.7863736679940324215607420213982, -0.0000033656243151182583405463328000383
0, -26.094361926054232600130044495449, -11.022752876224010373586983854075, 0.0000077508459792499219645213236865318]
B =[0;0;0.88636549407296896004815441721882; -2.0412505326340757878851343018816]
C =[ 1.0, 0, 0, 0; 1.0, 0, 1.0, 0]
D =[ 0; 0]
sys = ss(A,B,C,D)